Grillwork assembly guide pipe expanded connection method based on coaxial offset detection

Abstract

The invention provides a grillwork assembly conduit expanded connection method based on coaxial offset detection, which comprises the following steps: installing a detection end of a pressure sensor on an expanded connection flap, and detecting a plurality of first pressures of expanded connection between the expanded connection flap and a buffer tube before expanded connection; calculating a first coaxial offset between a plurality of expanded connection petals and a buffer tube according to the plurality of first pressures; and if the first coaxial offset is enough to enable the expanded connection to be unqualified, a first offset direction is obtained, and the distance of the first coaxial offset is adjusted in the direction opposite to the first offset direction. On the basis of the steps, the expanded connection push rod, the expanded connection petals and the buffer pipe can be adjusted to be coaxial enough, and the phenomenon that the expanded connection process is unqualified due to coaxial offset is avoided. Therefore, the probability of qualified expanded connection is improved; and the grillwork assembly structure after expanded connection has enough strength.

Description

Technical Field

[0001] This invention generally relates to the field of catheter expansion technology, and specifically to a method for expanding catheters in a grid assembly based on coaxial offset detection. Background Technology

[0002] Existing nuclear fuel skeleton assemblies include grid assemblies, which have multiple square holes. In actual operation, some of these square holes need to be selected first, and conduits need to be installed inside them. These conduits include inner and outer conduits. They can be pre-jointed and fixed together before being welded to the grid assembly. Alternatively, the outer conduit can be welded to the grid assembly, and the inner conduit placed inside the outer conduit, with the portions extending out of the grid assembly then joined together.

[0003] Existing expansion joint processes include: Insert the inner catheter into the outer catheter; insert the thinner end of the expansion push rod (which is thicker at one end and thinner at the other) into the expansion flap; insert the expansion push rod and the expansion flap into the inner catheter; continue inserting the expansion push rod into the expansion flap, with the thicker end entering the expansion flap, causing the expansion flap to open and abut against the inner wall of the inner catheter, causing the inner and outer catheters to undergo plastic deformation and form an expansion bulge.

[0004] The aforementioned expansion process requires ensuring the coaxiality of the expansion pusher, expansion flap, and inner and outer guide tubes. However, in actual manufacturing, the impact of coaxial offset on the expansion process is often overlooked. When the coaxial offset exceeds the allowable error range, different expansion flaps will exert significant differences in pressure on different parts of the inner guide tube, leading to irregular expansion shape and suboptimal grid assembly structural strength. This increases the likelihood of grid assembly failure during nuclear reaction, thereby increasing the risk of a nuclear accident. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for expanding and connecting conduits of lattice components based on coaxial offset detection.

[0006] This invention provides a method for expanding and connecting conduits in a grid assembly based on coaxial offset detection.

[0007] A buffer tube is installed inside a guide tube; an expansion push rod and multiple expansion flaps are installed inside the buffer tube. During the expansion process, the buffer tube is deformed and thus fixed to the guide tube. Depending on the insertion depth of the expansion push rod into the multiple expansion flaps, the multiple expansion flaps and the buffer tube have a contact state before expansion and an expansion state during the expansion process. When the insertion depth is less than a set depth, it is in a contact state, and the buffer tube does not undergo plastic deformation. When the insertion depth is greater than or equal to the set depth, it is in an expansion state, and the buffer tube undergoes plastic deformation under the pressure of the expansion flaps, thereby fixing it to the guide tube. Each of the multiple expansion flaps is equipped with a pressure sensor detection end for detecting the pressure between the expansion flaps and the buffer tube. The methods include: Adjust the insertion depth of the expansion push rod between multiple expansion flaps so that the multiple expansion flaps are in contact with the buffer tube; The detection measures the multiple first pressures between the multiple expansion flaps and the inner wall of the buffer tube when multiple expansion flaps are in contact with the buffer tube. Calculate the first coaxial offset between the multiple expansion joints and the buffer tube based on the multiple first pressures; Determine the magnitude of the first coaxial offset and the coaxial offset threshold; the coaxial offset threshold is: the maximum coaxial offset between multiple expansion joints and the buffer tube under the condition that the expansion joint is qualified. If the first coaxial offset is greater than the coaxial offset threshold, then the first offset direction between the multiple expansion joints and the buffer tube is obtained; The expansion joint device drives the expansion joint flap to move in the opposite direction of the first offset direction by the distance of the first coaxial offset.

[0008] According to the technical solution provided by the present invention, the calculation of the first coaxial offset between the expansion joint push rod and the expansion joint flap and the buffer tube based on multiple first pressures includes: Multiple pressure vectors for expansion joints are generated based on multiple first pressures; the vector direction of the pressure vectors is perpendicular to the inner wall of the buffer tube, and points from the corresponding expansion joint to the inner wall of the buffer tube at the position where the expansion joint abuts. The first composite vector is obtained by superimposing the multiple pressure vectors. The first coaxial offset is obtained based on the magnitude of the first composite vector.

[0009] According to the technical solution provided by the present invention, the first coaxial offset is obtained based on the magnitude of the first composite vector, including: Obtain the contour shape of the expansion push rod and the insertion depth of inserting the multiple expansion flaps; The first coaxial offset is predicted by inputting the contour shape, insertion depth, and magnitude of the first composite vector into the prediction model; the prediction model is used to predict the coaxial offset based on the input contour shape, insertion depth, and magnitude of the vector.

[0010] According to the technical solution provided by the present invention, obtaining the contour shape of the expansion joint push rod includes: Take an image of the expansion joint push rod to obtain the first image; The first image is binarized and edge detected sequentially to obtain the initial contour edges; The contour shape is obtained by extracting the initial contour edge.

[0011] According to the technical solution provided by the present invention, the contour shape is extracted based on the initial contour edge, including: The initial contour edges are subjected to symmetry axis detection to obtain the initial contour symmetry axis; The edge of the initial contour is divided into two contour generatrices along the axis of symmetry of the initial contour. Calculate the curvature of each point on the generatrix of the contour, and obtain the two points with non-zero curvature and the greatest distance from each other to obtain the two contour edge points; The portion of the generatrix of the contour located between two edge points of the contour is taken as the contour shape.

[0012] According to the technical solution provided by the present invention, the contour shape is extracted based on the initial contour edge, including: Perform line detection on the initial contour edge to extract all straight lines in the initial contour edge; All straight lines are removed from the initial contour edge to obtain the tapered contour. Clustering was performed on the tapered portion contour to obtain two clusters; Use all the pixels in one of the clusters as the outline shape.

[0013] According to the technical solution provided by the present invention, before moving the expansion joint flap in the opposite direction of the first offset direction by the distance of the first coaxial offset, the method further includes: Adjust the insertion depth of the expansion push rod between multiple expansion flaps to separate the multiple expansion flaps from the inner wall of the buffer tube.

[0014] According to the technical solution provided by the present invention, it also includes: Adjust the insertion depth of the expansion push rod between multiple expansion flaps so that the multiple expansion flaps and the buffer tube are in an expanded state; When multiple expansion valves and the buffer tube are in an expanded state, multiple second pressures are detected between the multiple expansion valves and the inner wall of the buffer tube; Based on multiple second pressures, determine whether the current expansion process has met the unqualified conditions; If the unqualified conditions are not met, then obtain the second offset direction between multiple expansion joints and the buffer tube; The expansion joint device drives the expansion joint flap to move in the opposite direction of the second offset direction by the distance of the second coaxial offset.

[0015] According to the technical solution provided by the present invention, determining whether the current expansion process has met the unqualified conditions based on multiple second pressures includes: If at least one of the second pressures is less than the first pressure, the current expansion joint process is deemed to have met the unqualified condition; otherwise, proceed to the following steps: The second coaxial offset is calculated based on multiple second pressures; If the second coaxial offset is greater than the coaxiality threshold, the current expansion process is determined to meet the unqualified conditions; otherwise, the current expansion process is determined to not meet the unqualified conditions.

[0016] The beneficial effects of this invention are as follows: To address the misalignment issue during the expansion joint of the buffer tube and guide tube, this invention considers installing a pressure sensor on the expansion joint flap and detecting multiple first pressures between the expansion joint flap and the buffer tube before expansion. Based on these first pressures, multiple first coaxial offsets between the expansion joint flap and the buffer tube are calculated. If the first coaxial offset is sufficient to cause expansion failure, a first offset direction is obtained, and the distance of the first coaxial offset is adjusted in the opposite direction. Based on these steps, the expansion push rod, expansion joint flap, and buffer tube can be adjusted to be sufficiently coaxial, preventing expansion failure due to coaxial offset. This increases the success rate of expansion and ensures sufficient strength in the expanded lattice assembly structure. Attached Figure Description

[0017] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the catheter expansion process; Figure 2 This is a cross-sectional view of the catheter expansion process; Figure 3 This is a schematic diagram of an expansion joint push rod; Among them: 1. Expansion push rod; 2. Expansion flap; 3. Buffer tube; 4. Guide tube; 5. Threaded rod; 6. Connecting part; 11. Coarse end; 12. Tapered part; 13. Fine end. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] refer to Figure 1-3 The actual expansion process involves placing the buffer tube 3 inside the guide tube 4, and then extending the expansion push rod 1 and the expansion flap 2 into the buffer tube 3.

[0021] refer to Figure 2 The expansion joint 2 has 4 segments, which are evenly distributed.

[0022] refer to Figure 3 The expansion push rod 1 has a thick end 11, a tapered portion 12, and a thin end 13, the contours of which are smoothly connected. The thin end is positioned between multiple expansion segments 2.

[0023] As the insertion depth of the expansion push rod 1 into the expansion flap 2 increases, the conical part causes the multiple expansion flaps 2 to move away from each other, so that the multiple expansion flaps abut against multiple different parts of the inner wall of the buffer tube 3.

[0024] Continue to increase the insertion depth of the expansion push rod 1 until the insertion depth is greater than the set depth; during this process, multiple expansion petals 2 continue to move away from each other, increasing the pressure on the inner wall of the buffer tube 3, causing the buffer tube 3 to deform, and then transmitting the pressure to the guide tube 4, further driving the guide tube 4 to deform, thus completing the expansion process.

[0025] After the expansion joint is completed, the deformed parts of the buffer tube 3 and the guide tube 4 form an expansion bulge, which fixes the buffer tube 3 and the guide tube 4 relative to each other.

[0026] refer to Figure 1 This invention provides a method for expanding and connecting conduits in a grid assembly based on coaxial offset detection.

[0027] This method is designed based on the above structure. In order to achieve the corresponding technical effect, in this embodiment: the buffer tube 3 is set inside the guide tube 4; the expansion push rod 1 and multiple expansion flaps 2 are set inside the buffer tube 3. During the expansion process, the buffer tube 3 is deformed and thus expanded and fixed to the guide tube 4; depending on the different insertion depths of the expansion push rod 1 into the multiple expansion flaps 2, the multiple expansion flaps 2 and the buffer tube 3 have a contact state before expansion and an expansion state during the expansion process; when the insertion depth is less than the set depth, it is in a contact state and the buffer tube 3 does not undergo plastic deformation; when the insertion depth is greater than or equal to the set depth, it is in an expansion state, and the buffer tube 3 undergoes plastic deformation under the pressure of the expansion flaps 2, thereby expanding and fixing to the guide tube 4; each of the multiple expansion flaps 2 is equipped with a detection end of a pressure sensor to detect the pressure between the expansion flaps 2 and the buffer tube 3.

[0028] It should be noted that: when the insertion depth is less than the set depth, it is in the contact state; otherwise, it is in the expansion state. In this embodiment, the state of the buffer tube before plastic deformation and the expansion joint is collectively referred to as the contact state; the state of the buffer tube during plastic deformation and the expansion joint is collectively referred to as the expansion state. Therefore, the set depth is the maximum insertion depth of the expansion push rod 1 when the expansion joint abuts against the inner wall of the buffer tube without plastic deformation. Since the existing expansion push rod 1 has various tapered contour shapes, it is necessary to obtain the set depth corresponding to each type of expansion push rod 1 through experimental measurement.

[0029] The methods include: S1: Adjust the insertion depth of the expansion push rod 1 between multiple expansion flaps 2 so that the multiple expansion flaps 2 are in contact with the buffer tube 3; S2: Detect multiple first pressures between the multiple expansion flaps 2 and the inner wall of the buffer tube 3 when the multiple expansion flaps 2 and the buffer tube 3 are in contact. S3: Calculate the first coaxial offset between the multiple expansion joints 2 and the buffer tube 3 based on the multiple first pressures; S4: Determine the magnitude of the first coaxial offset and the coaxial offset threshold; Q1-1: If the first coaxial offset is greater than the coaxial offset threshold, then obtain the first offset direction between the multiple expansion joints 2 and the buffer tube 3; Specifically, the coaxial offset threshold is the maximum coaxial offset between multiple expansion joints 2 and the buffer tube 3 when the expansion joint is qualified.

[0030] If the first coaxial offset is greater than the coaxial offset threshold, it means that the current offset will cause the expansion joint to be unqualified; therefore, adjustment is required.

[0031] In this embodiment, the vector direction of the first composite vector is used as the first offset direction.

[0032] Q1-2: Drive the expansion joint 2 to move the distance of the first coaxial offset in the opposite direction of the first offset direction.

[0033] Q2-1: If the first coaxial offset is less than or equal to the coaxial offset threshold, then there is no need to adjust the coaxial offset and the expansion process continues.

[0034] If the coaxial offset is less than or equal to the coaxial offset threshold, it means that the current offset may be a small error and is not enough to cause the expansion process to fail; therefore, considering the limited adjustment accuracy, no further adjustment will be made.

[0035] In some implementations, the coaxial offset threshold is obtained in the following ways: Design corresponding experiments to obtain the coaxial offset threshold, including: The expansion push rod 1 and expansion flap 2 are inserted into the buffer tube 3, and the relative positions of the expansion push rod 1 and expansion flap 2 with the buffer tube 3 are adjusted to achieve different coaxial offsets; during this process, the coaxial offset at each position is actually measured.

[0036] Multiple sample groups are designed. In each sample group, the expansion push rod 1, expansion flap 2 and buffer tube 3 maintain a fixed coaxial offset. The coaxial offset is different for each sample group. While maintaining their respective coaxial offsets, the expansion joint test was completed, and the subsequent inspection was conducted to determine whether the expansion was qualified. Select the sample groups that meet the expansion criteria, and use the largest coaxial offset among them as the coaxial offset threshold.

[0037] Based on the above steps, the coaxial offset threshold can be obtained relatively accurately. In the actual expansion process, it can be used as a standard to determine whether the coaxial offset needs to be adjusted, thus ensuring the success rate of expansion.

[0038] Further, the first coaxial offset between the expansion push rod 1 and the expansion flap 2 and the buffer tube 3 is calculated based on multiple first pressures, including: Multiple pressure vectors for expansion joint 2 are generated based on multiple first pressures; the multiple pressure vectors are vector superimposed to obtain a first comprehensive vector; The first coaxial offset is obtained based on the magnitude of the first composite vector.

[0039] In order to calculate the coaxial offset, this embodiment considers utilizing the vector characteristics of pressure to generate a corresponding pressure vector based on multiple pressure values ​​detected by the pressure sensor.

[0040] The pressure vector is perpendicular to the inner wall of the buffer tube 3, and is directed by the corresponding expansion joint 2 to the inner wall of the position where the buffer tube 3 and the expansion joint 2 abut.

[0041] By superimposing multiple pressure vectors, the component forces of the multiple pressure vectors can be canceled out, leaving only the final resultant force. The magnitude of the final resultant force is equal to the magnitude of the first composite vector; the direction of the first composite vector is the direction of the offset.

[0042] refer to Figure 2 The thick arrows represent unit vectors in each direction. By multiplying the detected pressures by their corresponding unit vectors, the pressure vector can be obtained.

[0043] Based on the preceding text, the expansion joint 2 has four evenly distributed segments, such that the movement directions of adjacent expansion joint segments 2 during expansion are perpendicular to each other. See the attached document for details. Figure 2 The arrow in the diagram. Therefore, in this embodiment, a rectangular coordinate system is established with the plane perpendicular to the expansion push rod 1 as the reference; the origin is located on the axis of the expansion push rod 1, the horizontal axis is horizontal, and the vertical axis is vertical. Thus, each unit vector can be represented as: (1,0), (0,1), (-1,0), (0,-1). Each unit vector defaults to starting from the origin and ending at the coordinate point. Figure 2 For easier observation, each unit vector is translated to the corresponding expansion lobe position.

[0044] Further, based on the magnitude of the first composite vector, the first coaxial offset is obtained, including: Obtain the outline shape of the expansion push rod 1 and the insertion depth of the multiple expansion flaps 2; The first coaxial offset is predicted by inputting the contour shape, insertion depth, and magnitude of the first composite vector into the prediction model; the prediction model is used to predict the coaxial offset based on the input contour shape, insertion depth, and magnitude of the vector.

[0045] Specifically, multiple expansion joints 2 are all connected to the same connecting part 6; the thin end of the expansion push rod 1 is fixedly connected to a threaded rod 5, which is threadedly connected to the connecting part 6. The relative positions of the threaded rod 5, the expansion push rod 1, and the connecting part 6 are adjusted by rotating the threaded rod 5; thereby achieving the purpose of adjusting the insertion depth of the expansion push rod 1 between the multiple expansion joints 2.

[0046] The connecting part 6 is fixedly mounted on the expansion device (e.g., a robotic arm). The expansion device moves the expansion push rod 1, the threaded rod 5, the multiple expansion flaps 2 and the connecting part 6 to adjust the coaxial offset.

[0047] Based on the above structural design, the insertion depth can be obtained by measuring the change in length of the threaded rod 5 extending out of the connecting part 6 away from the expansion push rod 1.

[0048] For example, if the initial extension length is 2cm and the insertion depth is 2cm, and after adjustment the extension length to 4cm, then the insertion depth is 4cm.

[0049] Because the insertion depth of the expansion push rod 1 is different, the contact points between the expansion flap 2 and the conical part are different, which in turn causes the multiple expansion flaps 2 to open to different degrees, and the pressure transmitted to the buffer tube 3 is also different.

[0050] Moreover, the existing technology already has expansion push rods 1 with various contour shapes. When the insertion depth is different, the pressure applied to the expansion flap 2 will also be different for expansion push rods 1 with different contour shapes.

[0051] In summary, to determine the coaxial offset, it is necessary to consider not only the first composite vector, but also the contour shape of the expansion push rod 1 and the insertion depth of the multiple expansion flaps 2.

[0052] However, existing technologies lack methods for calculating the conversion relationships between these three elements. Therefore, this embodiment uses a neural network model to fit the conversion relationships between them.

[0053] The prediction model is a neural network model trained with a large amount of experimental data. Its training samples include expansion joint push rods with different contour shapes, and the correspondence between the pressure vector magnitude detected at different insertion depths and the actual measured coaxial offset.

[0054] Specific methods for obtaining prediction models include: Obtain expansion joint push rods 1 with various profile shapes; For each profile shape of the expansion push rod 1, multiple sets of experiments were designed. Before the experiment, each set was set with a different coaxial offset (actively set as a known quantity), and its own coaxial offset was always maintained. During the experiment, the insertion depth was adjusted and multiple sets of pressure values ​​were measured; each set of pressure values ​​included the pressure detected by the pressure sensor at two points on each expansion joint. Calculate the combined vector of multiple pressure values ​​separately to obtain the sample combined vector; Then, the contour shape, insertion depth, and sample composite vector are combined to form training samples.

[0055] In this embodiment, the outline shape of the expansion joint push rod 1 is obtained by capturing an image of the expansion joint push rod 1. After capturing the image, the outline shape of the expansion joint push rod 1 is obtained after binarization and edge detection.

[0056] The prediction model uses a CNN-type neural network, taking the contour shape, insertion depth, and sample composite vector as training sample inputs, and the corresponding coaxial offset as label data. The predicted value of the coaxial offset is used as the output to train the neural network model.

[0057] In this embodiment, the methods for obtaining training samples are limited, and it requires staff to manually take images of the expansion joint push rod 1. Therefore, a CNN-type neural network is used. Its advantages are: the amount of data required for training is relatively small, and after training, it has strong adaptability to outliers and better robustness. It supports random rotation, translation, and scaling of images, and has stronger adaptability when dealing with manually taken images.

[0058] After training, the prediction model required in this embodiment is obtained.

[0059] Further, the contour shape of the expansion joint push rod 1 is obtained, including: Take an image of the expansion push rod 1 to obtain the first image; during the shooting, the extension direction of the expansion push rod is perpendicular to the shooting direction.

[0060] The first image is binarized and edge detected sequentially to obtain the initial contour edge; in this embodiment, Canny edge detection is used.

[0061] The contour shape is obtained by extracting the initial contour edge.

[0062] In the first embodiment, the contour shape is extracted based on the initial contour edge, including: The initial contour edges are subjected to symmetry axis detection to obtain the initial contour symmetry axis, including: Construct the covariance matrix based on the initial contour edges (at this point, a set of coordinates of multiple edge points); Eigenvalue decomposition of the covariance matrix yields multiple eigenvalues ​​and multiple corresponding eigenvectors; Calculate the centroid of the initial contour edges; The straight line passing through the centroid and parallel to the eigenvector corresponding to the largest eigenvalue is the axis of symmetry of the initial contour.

[0063] The edge of the initial contour is divided into two contour generatrices along the axis of symmetry of the initial contour. Calculate the curvature of each point on the generatrix of the contour, and obtain the two points with non-zero curvature and the greatest distance from each other to obtain the two contour edge points; The portion of the generatrix of the contour located between two edge points of the contour is taken as the contour shape.

[0064] Based on the above steps, the edge of the expansion joint push rod 1 is extracted using binarization and edge detection. Then, the edge is divided into two parts according to the axis of symmetry using symmetry detection. The curvature of each point in one part is calculated, and the boundary between the thick end, the tapered part, and the thin end is distinguished based on the two points with non-zero curvature and the greatest distance. Thus, the contour shape of the tapered part can be extracted.

[0065] In the second embodiment, the contour shape is extracted based on the initial contour edge, including: Perform line detection on the initial contour edge to extract all straight lines in the initial contour edge; All straight lines are removed from the initial contour edge to obtain the tapered contour. The tapered contour is clustered (using the K-means algorithm, where K=2 in this embodiment) to obtain two clusters; Use all the pixels in one of the clusters as the outline shape.

[0066] In this embodiment, considering that the image shooting direction is perpendicular to the extension direction of the expansion push rod, it can be known that the edges of the thick and thin ends are straight lines, while the edge of the tapered part is curved. Therefore, the contour of the tapered part can be obtained by detecting and eliminating straight lines.

[0067] Specifically, the process of line detection includes: Perform a Hough transform on the initial contour edge image to detect all line segments in the image; Set a straight line length threshold (i.e., the diameter of the thick end and the thin end, and the length along the extension direction of the expansion push rod) and an angle threshold (in this embodiment, there are only two cases: 90 degrees or parallel) to filter out the straight line segments that meet the requirements. Mark the selected line segments on the edge of the initial contour and complete the extraction.

[0068] After detecting all straight lines, removing them yields the tapered contour, consisting of two symmetrical contour shapes. Since the two contour shapes are disconnected after the straight lines have been removed, they can be distinguished using clustering. Finally, all pixels in one of the clusters are used as the contour shape.

[0069] Since both the thick and thin ends of the expansion push rod 1 are cylindrical, their length has no effect on the pressure during the expansion process. Therefore, in this embodiment, the corresponding thick and thin ends are excluded to avoid affecting the training accuracy of the prediction model. This allows the prediction model to predict the coaxial deviation based on the contour shape of the tapered part, improving the accuracy of the prediction.

[0070] The first implementation is applicable to cases where the contour shape of the tapered part is arbitrary; that is, the contour shape can be extracted in any case (as long as the contour of the expansion push rod is axisymmetric).

[0071] The second implementation method is applicable when the contour edges of the tapered portion are all curved. When the contour edges of the tapered portion are all curved, the relatively simpler second implementation method can reduce the amount of calculation and extract the contour edges more quickly.

[0072] When the contour of the tapered portion contains a portion of straight lines, the second implementation will remove part of the tapered portion's contour and thus fail; in this case, the first implementation should be used.

[0073] Furthermore, before moving the expansion joint 2 in the opposite direction of the first offset direction by the distance of the first coaxial offset, the procedure further includes: Adjust the insertion depth of the expansion push rod 1 between the multiple expansion flaps 2 so that the multiple expansion flaps are separated from the inner wall of the buffer tube 3.

[0074] Specifically, during the process of adjusting the coaxial offset in this step, since the expansion joint has not yet started, in order to avoid relative sliding between the expansion joint flap and the inner wall of the buffer tube during the adjustment process, which would damage the buffer tube, in this embodiment, the insertion depth of the expansion joint push rod 1 is first reduced, causing the expansion joint flap to separate from the inner wall of the buffer tube 3; then, after adjusting the coaxial offset, the insertion depth is increased to make the expansion joint flap 2 abut against the inner wall of the buffer tube.

[0075] Furthermore, it also includes: Adjust the insertion depth of the expansion push rod 1 between the multiple expansion flaps 2 so that the multiple expansion flaps 2 and the buffer tube 3 are in an expanded state; When multiple expansion joints 2 and buffer tube 3 are in an expanded joint state, multiple second pressures are detected between the multiple expansion joints 2 and the inner wall of the buffer tube 3. Based on multiple second pressures, determine whether the current expansion process has met the unqualified conditions; If the unqualified conditions are not met, then obtain the second offset direction between multiple expansion joints 2 and buffer tube 3; The expansion joint device drives the expansion joint 2 to move in the opposite direction of the second offset direction by the distance of the second coaxial offset.

[0076] Before the expansion joint, this embodiment adjusts the expansion joint 2 and the buffer tube to be almost coaxial; theoretically, the expansion joint process should not lead to failure. However, in reality, the inner wall of the buffer tube 3 abuts against multiple expansion joints 2, and there are still some uncontrollable factors that can cause the expansion joint to fail. For example, uncontrollable factors include: the different stresses between the expansion push rod 1 and different expansion joints 2 when it is inserted, the thickness error between different expansion joints 2, the structural strength error between different parts of the buffer tube, and other unknown factors.

[0077] The aforementioned factors can cause one part of the inner wall of the buffer tube to deform first during the process of increasing the insertion depth, resulting in a smaller increase in pressure on the inner wall on the opposite side, thus producing unequal deformation. When the difference in deformation is too large, it will cause the bulge shape to be irregular, ultimately leading to unqualified expansion joint.

[0078] This embodiment takes into account the above situations. During the expansion process, it first determines whether the expansion process has failed. If the expansion process has not yet failed, adjustments can be made to avoid failure. Specifically, the pressure during the expansion process is collected using the detection end of the installed pressure sensor, and then the second coaxial offset and the second offset direction are calculated. Adjustments are then made again if the second coaxial offset is not greater than the coaxial offset threshold. This can compensate for differences in deformation at different parts and reduce the probability of expansion failure. Based on the above steps, the pass rate during the expansion process can be improved.

[0079] Furthermore, based on multiple second pressures, it is determined whether the current expansion process has met the conditions for non-compliance, including: If at least one of the second pressures is less than the first pressure, the current expansion joint process is deemed to have met the unqualified condition; otherwise, proceed to the following steps: The second coaxial offset is calculated based on multiple second pressures; If the second coaxial offset is greater than the coaxiality threshold, the current expansion process is determined to meet the unqualified conditions; otherwise, the current expansion process is determined to not meet the unqualified conditions.

[0080] Specifically, if the expansion joint is not up to standard, cracks may occur at the point where the buffer tube abuts the expansion joint, which may lead to a significant reduction in the pressure between the buffer tube and the expansion joint, or even less than the pressure in the abutment state.

[0081] When the expansion joint is not up to standard, the buffer tube may not have cracked, but due to excessive coaxial offset, the deformation on one side of the buffer tube is already greater than the required deformation.

[0082] Based on the above, in this embodiment, if neither of the above two conditions is met during the expansion joint process, it can be determined that the unqualified conditions have not been met, and adjustments can be made to reduce the probability of unqualified expansion joints.

[0083] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for expanding and connecting conduits in a lattice assembly based on coaxial offset detection, characterized in that, The buffer pipe (3) is arranged in the guide pipe (4); the expansion push rod (1) and the plurality of expansion petals (2) are arranged in the buffer pipe (3), and the buffer pipe (3) is deformed to be expanded and fixed with the guide pipe (4) during the expansion process; according to different insertion depths of the expansion push rod (1) inserted between the plurality of expansion petals (2), the plurality of expansion petals (2) and the buffer pipe (3) have an abutting state before expansion and an expansion state during expansion; when the insertion depth is less than the set depth, the abutting state is in the abutting state, and the buffer pipe (3) does not produce plastic deformation; when the insertion depth is greater than or equal to the set depth, the expansion state is in the expansion state, and the buffer pipe (3) produces plastic deformation under the pressure of the expansion petals (2), thereby being expanded and fixed with the guide pipe (4); the plurality of expansion petals (2) are respectively provided with detection ends of pressure sensors for detecting the pressure between the expansion petals (2) and the buffer pipe (3); The method comprises: Adjusting the insertion depth of the expansion push rod (1) inserted between the plurality of expansion petals (2) to make the plurality of expansion petals (2) and the buffer pipe (3) in the abutting state; Detecting a plurality of first pressures between the plurality of expansion petals (2) and the inner wall of the buffer pipe (3) when the plurality of expansion petals (2) and the buffer pipe (3) are in the abutting state; Calculating a first coaxial offset between the plurality of expansion petals (2) and the buffer pipe (3) according to the plurality of first pressures; Judging the size of the first coaxial offset and a coaxial offset threshold value; the coaxial offset threshold value is the maximum coaxial offset between the plurality of expansion petals (2) and the buffer pipe (3) in the case of qualified expansion; If the first coaxial offset is greater than the coaxial offset threshold value, a first offset direction between the plurality of expansion petals (2) and the buffer pipe (3) is obtained; The expansion device drives the expansion petals (2) to move in the opposite direction of the first offset direction by the distance of the first coaxial offset.

2. A method of expanding a grid assembly conduit based on coaxial offset detection, as claimed in claim 1, wherein, Calculating the first coaxial offset of the expansion push rod (1) and the expansion petals (2) and the buffer pipe (3) according to the plurality of first pressures comprises: Generating a pressure vector of the plurality of expansion petals (2) according to the plurality of first pressures; the vector direction of the pressure vector is perpendicular to the inner wall of the buffer pipe (3), and the pressure vector is directed to the inner wall of the buffer pipe (3) and the abutting position of the expansion petals (2); Vector superposition is performed on the plurality of pressure vectors to obtain a first comprehensive vector; The first coaxial offset is obtained based on the module of the first comprehensive vector.

3. A method of expanding a grid assembly conduit based on coaxial offset detection, according to claim 2, wherein, The first coaxial offset is obtained based on the module of the first comprehensive vector, comprising: Obtaining the profile shape of the expansion push rod (1) and the insertion depth of the plurality of expansion petals (2); The profile shape, insertion depth, and module of the first comprehensive vector are input into a prediction model to predict the first coaxial offset; the prediction model is used to predict the coaxial offset according to the input profile shape, insertion depth, and vector module.

4. A method of expanding a grid assembly conduit based on coaxial offset detection according to claim 3, wherein, Obtaining the profile shape of the expansion push rod (1) comprises: Taking an image of the expansion push rod (1) to obtain a first image; The first image is sequentially binarized and edge detected to obtain an initial contour edge; The profile shape is extracted according to the initial contour edge.

5. A method of expanding a grid assembly conduit based on coaxial offset detection, as claimed in claim 4, wherein, According to the initial contour edge extraction contour shape, comprising: The initial contour edge symmetry axis detection, get initial contour symmetry axis; Along the initial contour symmetry axis will initial contour edge into two contour generatrix; Calculate the curvature of each point on the contour generatrix, and obtain the two points with curvature not equal to 0 and the farthest distance, get two contour edge points; Cut off the part between the two contour edge points on the contour generatrix as the contour shape.

6. A method of expanding a grid assembly conduit based on coaxial offset detection, as claimed in claim 4, wherein, According to the initial contour edge extraction contour shape, comprising: The initial contour edge straight line detection, extraction get all straight lines in the initial contour edge; In the initial contour edge, all straight lines are eliminated, and the conical part contour is obtained; The conical part contour is clustered to obtain two clusters; All pixel points in one of the clusters are taken as the contour shape.

7. A method of expanding a grid assembly guide tube based on coaxial offset detection as defined in claim 1, wherein, Before driving the expansion joint segment (2) to move in the opposite direction of the first offset direction by a distance of the first coaxial offset amount, further comprising: Adjust the insertion depth of the expansion joint push rod (1) inserted between the plurality of expansion joint segments (2), so that the plurality of expansion joint segments and the inner side wall of the buffer pipe (3) are separated from each other.

8. A method of expanding a grid assembly conduit based on coaxial offset detection, as claimed in claim 1, wherein, Further comprising: Adjust the insertion depth of the expansion joint push rod (1) inserted between the plurality of expansion joint segments (2), so that the plurality of expansion joint segments (2) and the buffer pipe (3) are in the expansion state; Detect the plurality of second pressures between the plurality of expansion joint segments (2) and the inner side wall of the buffer pipe (3) when the plurality of expansion joint segments (2) and the buffer pipe (3) are in the expansion state; Based on the plurality of second pressures, determine whether the current expansion process has met the unqualified condition; If the unqualified condition is not met, obtain the second offset direction between the plurality of expansion joint segments (2) and the buffer pipe (3); The expansion joint device drives the expansion joint segment (2) to move in the opposite direction of the second offset direction by a distance of the second coaxial offset amount.

9. A method of expanding a grid assembly conduit based on coaxial offset detection according to claim 8, wherein, Based on the plurality of second pressures, determine whether the current expansion process has met the unqualified condition, comprising: If at least one of the second pressures is less than the first pressure, it is determined that the current expansion process has met the unqualified condition, otherwise the following steps are performed: Based on the plurality of second pressures, the second coaxial offset amount is calculated; If the second coaxial offset amount is greater than the coaxiality threshold, it is determined that the current expansion process has met the unqualified condition; otherwise, it is determined that the current expansion process has not met the unqualified condition.

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